[chore](build) Update doris-skills submodule - #64240

…0582)

### Background

`doris-skills` is a submodule that points at apache/doris-skills, the
Apache Doris repository of agent skills: instructions and scripts that
coding agents such as Claude Code and Codex load for Doris tasks.
Nothing builds from it; it is checked out on request (`git submodule
update --init doris-skills`) and by the CI jobs that clone every
submodule. This repository pins `c0aca2f` (apache/doris-skills#2, June),
which has three skills.

### What problem does this PR solve?

Issue Number: None
Related PR: #64240 (the previous update of this pointer), #70422 (moves
the same pointer to `0b36dcb` and adds the `AGENTS.md` guidance;
conflicts with this PR on that line), apache/doris-skills#17 (the commit
this PR pins)
PR Type: Build/CI/Chore

Problem Summary:

Since `c0aca2f`, doris-skills has merged 13 PRs that add four skills,
for debugging, local PR review, development, and PR descriptions, and a
checkout of this repository still gets none of them. This PR moves the
pointer to `c353d71`, the tip of doris-skills `main`, and changes
nothing else. Builds, tests, and Doris users see no change.

| | Skills in `doris-skills/skills/` |
|---|---|
| master (`c0aca2f`) | `doris-architecture-advisor`,
`doris-best-practices`, `doris-profile-reader` |
| this PR (`c353d71`) | `develop-with-evidence`,
`doris-architecture-advisor`, `doris-best-practices`, `doris-debug`,
`doris-pr-description`, `doris-profile-reader`, `doris-repo-review` |

### Details

- **Affected:** Only the `doris-skills` pointer. The CI jobs that clone
every submodule (`submodules: recursive` in `be-ut-mac.yml`,
`build-extension.yml`, `build-thirdparty.yml`, `build-ui.yml`, and
`checkstyle.yaml`, and `git submodule update --init --recursive --depth
1` in the performance pipeline's `compile.sh`) clone doris-skills at
`c353d71` without reading it; `build.sh` and `run-be-ut.sh` update only
the `contrib/` submodules they name.
- **Developer and release impact:** Developers who check out the
submodule get the seven skills at `c353d71`, about 2.3 MB; existing
checkouts keep their commit until the next `git submodule update`.
Release builds don't change, since no script in this repository reads
`doris-skills`.
- **License and third-party:** None. doris-skills is an Apache-2.0
repository of the ASF, and no file from it is added to this tree.
- **Rollback:** Revert this PR; local submodule checkouts made meanwhile
do no harm.

### Testing

- `git ls-remote https://github.com/apache/doris-skills refs/heads/main`
returns `c353d71bc50d6c0baf1831dec33cbfa0abc64ef2`, the commit this PR
pins: the squash merge of apache/doris-skills#17, not a PR-only commit.
`c0aca2f` is its ancestor.
- A fresh clone of the URL in `.gitmodules`, checked out at `c353d71` as
`git submodule update --init doris-skills` does, holds the seven skills
in the table above.
- `python3 skills/doris-pr-description/scripts/check_pr.py --self-test`
at `c353d71` reports `Self-test: 11 examples in 10 files, 0 problems`.

### Notes for Reviewers

- The pointer moves over 13 commits of apache/doris-skills (#3 to #17),
+10,047 −45 in 114 files, each reviewed and merged there; the three
skills pinned today don't change. In this repository's diff, only the
pin itself needs checking.
- #70422 changes the same line, to `0b36dcb` (apache/doris-skills#16).
Whichever of the two merges second keeps `c353d71`.